Three-dimensional display apparatus

ABSTRACT

A three-dimensional display apparatus, including a backlight module, two panels, and a synchronization device, is provided. The backlight module has a light emitting side and sequentially emits a plurality of color light. Both panels are disposed at the light emitting side, and the first panel is disposed between the backlight module and the second panel. The first panel includes a first polarizer and a first liquid crystal substrate, and the first polarizer is disposed between the backlight module and the first liquid crystal substrate. The second panel includes a second liquid crystal substrate and a second polarizer, and the second liquid crystal substrate is disposed between the second polarizer and the first panel. The synchronization device is electrically connected to the backlight module and the two liquid crystal substrates. During a frame time, the backlight module and the two liquid crystal substrates are synchronously driven by the synchronization device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 98209055, filed on May 22, 2009. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of specification.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention generally relates to a display apparatus; morespecifically, to a three-dimensional display apparatus.

2. Description of Related Art

With recent advancements of display technologies, the research focus hasgradually shifted towards devices that can generate three-dimensional(3D) images.

FIG. 1A is an exploded view of a conventional 3D display apparatus.

Referring to FIG. 1A, a conventional 3D display apparatus 100 includes afirst panel 110, a second panel 120 and a cold cathode fluorescent lightsource 130 (placed in order). Between the first panel 110 and the secondpanel 120 there is a depth D. 3D image effects are generated due to theimage brightness difference between images formed by the first panel 110and the second panel 120, coupled with human visual illusion of thisscene. Observer P perceives the generated image as if the image islocated between the first panel 110 and the second panel 120. Thistechnology is commonly known as Depth-Fused 3D, or DFD.

More specifically, as shown in FIG. 1A, the image brightness values onthe first panel 110 and the second panel 120 are determined by theirrespective cross-sectional densities. The higher the panelcross-sectional density, the higher the brightness value; conversely,the image brightness value will be lower. Due to the lower imagebrightness value at a first location A1 of the first panel 110 withrespect to the image brightness value at a second location A2 of thesecond panel 120, the observer P perceives a deeper image there. Theperceived image will be located closer to the second panel 120 (fartheraway from the observer P). Similarly, the image brightness value at athird location A3 of the first panel 110 is higher than the imagebrightness value at a fourth location A4 of the second panel 120.Therefore, observer P observes a shallower image there, and theperceived image will be located closer to the first panel 110 (closer tothe observer P). FIG. 1B is a schematic perspective view of the firstand second panels of the 3D display found in FIG. 1A. Referring to FIG.1B, the first panel 110 and the second panel 120 each respectivelyincludes a polarizer 111,121, an active device array substrate 113,123,a color filter 115,125, and a substrate 117,127. It should be noted thata light ray L emanating from the cold cathode fluorescent light source130 travels sequentially through the polarizer 121 of the second panel120, the active device array substrate 123, the color filter 125, thesubstrate 127, the active device array substrate 113 of the first panel110, the color filter 115, the substrate 117, the polarizer 111, andthen the light ray L enters the eyes of the observer P.

The technology aforementioned makes use of two panels (the first panel110 and the second panel 120), where the panel transmittances of thefirst panel 110 and the second panel 120 are very low, at around 5%.Therefore, brightness value of the light ray L emanating from the coldcathode fluorescent light source 130 will be significantly reduced afterthe light ray L passes through the first panel 110 and the second panel120. In other words, there is a significant difference between the imagebrightness value the observer P perceives and the original brightnessvalue of the cold cathode fluorescent light source 130. Hence, when theneed to present more brilliant images arises, the cold cathodefluorescent light source 130 must be turned quite bright, herebysignificantly increasing the power consumption of the 3D displayapparatus 100.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a 3D display apparatuscapable of generating quality 3D color images while featuring betterpanel transmission rate and lower power consumption.

The present invention provides a 3D display apparatus including abacklight module, a first panel, a second panel, and a synchronizationdevice. The backlight module has a light emitting side, and thebacklight module sequentially emits a plurality of color light. Thefirst panel is disposed at the light emitting side, and the first panelincludes a first polarizer and a first liquid crystal substrate. Thefirst polarizer is disposed between the first liquid crystal substrateand the backlight module. The second panel is disposed at the lightemitting side, and the first panel is disposed between the backlightmodule and the second panel. The second panel includes a second liquidcrystal substrate and a second polarizer, and the second liquid crystalsubstrate is disposed between the second polarizer and the first panel.The synchronization device is electrically connected to the backlightmodule, the first liquid crystal substrate, and the second liquidcrystal substrate. During a frame time, the synchronization devicesynchronously drives the backlight module and the first and secondliquid crystal substrates.

In one embodiment of the present invention, during the frame time, thesynchronization device aforementioned coordinates the color lightsequentially emitted by the backlight module with the image informationgenerated by the first and second liquid crystal substrates.

In one embodiment of the present invention, during the aforementionedframe time, the synchronization device receives a first driving signalfrom the backlight module and generates a second driving signal and athird driving signal, sends the second signal to the first liquidcrystal substrate, and sends the third driving signal to the secondliquid crystal substrate.

In one embodiment of the present invention, during the aforementionedframe time, the synchronization device receives a first driving signalfrom the first liquid crystal substrate and generates a second drivingsignal and a third driving signal, sends the second driving signal tothe backlight module, and sends the third driving signal to the secondliquid crystal substrate.

In one embodiment of the present invention, during the aforementionedframe time, the synchronization device receives a first driving signalfrom the second liquid crystal substrate and generates a second drivingsignal and a third driving signal, sends the second driving signal tothe backlight module, and sends the third driving signal to the firstliquid crystal substrate. In another embodiment of the invention, duringthe aforementioned frame time, the synchronization device generates afirst, second, and third driving signal and synchronously sends thethree signals to the backlight module, the first liquid crystalsubstrate, and the second liquid crystal substrate, respectively.

In one embodiment of the present invention, during the aforementionedframe time, the images generated by the first and second liquid crystalsubstrates are combined to generate a 3D image.

In one embodiment of the present invention, the aforementioned firstimage and second image have unequal image brightness values.

In one embodiment of the present invention, the three-dimensionaldisplay apparatus further includes a third liquid crystal substratedisposed between the first and second panels.

In one embodiment of the present invention, during the frame time, theaforementioned synchronization device coordinates the color lightsequentially emitted by the backlight module with the image informationdisplayed by the first, second, and third liquid crystal substrates.

In one embodiment of the present invention, during the aforementionedframe time, the synchronization device receives a first driving signalfrom the first liquid crystal substrate and generates a second, third,and fourth driving signal, sends the second driving signal to thebacklight module, sends the third driving signal to the third liquidcrystal substrate, and sends the fourth driving signal to the secondliquid crystal substrate.

In one embodiment of the present invention, during the aforementionedframe time, the images generated by the first, second, and third liquidcrystal substrates are combined to generate a 3D image.

In one embodiment of the present invention, the image brightness valuesof the aforementioned first, second, and third images are all unequal.

In one embodiment of the present invention, the aforementioned backlightmodule includes matrix backlight units; each of backlight units includesone red light-emitting diode (LED), one green LED, and one blue LED.

In one embodiment of the present invention, the aforementioned firstliquid crystal substrate includes the first active device arraysubstrate, a first opposite substrate, and a first liquid crystal layer.The first active device array substrate includes a plurality of matrixfirst-pixel units, where each of the first-pixel units corresponds to aplurality of backlight units. The first opposite substrate is disposedopposite to the first active device array substrate. The first liquidcrystal layer is disposed between the first active device arraysubstrate and the first opposite substrate.

In one embodiment of the present invention, the aforementioned secondliquid crystal substrate includes a second active device arraysubstrate, a second opposite substrate, and a second liquid crystallayer. The second active device array substrate includes a plurality ofmatrix second-pixel units, where each of the second-pixel unit has aplurality of corresponding backlight units. The second oppositesubstrate is disposed opposite to the second active device arraysubstrate. The second liquid crystal layer is disposed between thesecond active device array substrate and the second opposite substrate.

In one embodiment of the present invention, the polarizing direction ofthe aforementioned first polarizer is substantially perpendicular to thepolarizing direction of the aforementioned second polarizer.

Based on the above, the 3D display apparatus of the present invention isspared of the poorly transmissive color filters. The 3D displayapparatus also replaces the conventional cold cathode fluorescent lightsource with a backlight module that sequentially emits a plurality ofcolor light. Therefore, the 3D display apparatus of the presentinvention possesses a higher transmission rate. Furthermore, the 3Ddisplay apparatus also includes a synchronization device which, during aframe time, synchronizes the driving of the backlight module and thefirst and second panels such that the emitted color light from thebacklight module can be coordinated with the image information generatedby the first and second panels. Consequently, quality color 3D imagesare generated.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1A is an exploded view of the conventional 3D display apparatus.

FIG. 1B is a schematic perspective view of the first and second panel ofthe 3D display apparatus in FIG. 1A.

FIG. 2 is an exploded view of an embodiment of the 3D display apparatusof the present invention.

FIG. 3 to FIG. 6 are schematic views that show the driving schemesbetween components of the 3D display apparatus in FIG. 2.

FIG. 7 is an exploded view of another embodiment of the 3D displayapparatus of the present invention.

DESCRIPTION OF EMBODIMENTS

FIG. 2 is an exploded view of an embodiment of the 3D display apparatusof the present invention. FIG. 3 to FIG. 6 are schematic views that showthe driving schemes between components of the 3D display apparatus inFIG. 2. In FIG. 3 to FIG. 6, only the backlight module 210, the firstliquid crystal substrate 250, the second liquid crystal substrate 260,and the synchronization device 280 of the 3D display apparatus 200 aredrawn in order to show the driving schemes between each component.Following, FIG. 2 and FIG. 3 are referenced to explain how the 3Ddisplay apparatus 200 is built. Referring to FIG. 2 and FIG. 3, this 3Ddisplay apparatus 200 includes the backlight module 210, the first panel220, the second panel 230, and the synchronization device 280. Thebacklight module 210 has a light emitting side B, and the backlightmodule 210 sequentially emits a plurality of color light (not drawn).The first panel 220 is disposed in the light emitting side B, and thefirst panel 220 includes a first polarizer 240 and a first liquidcrystal substrate 250; the first polarizer 240 is disposed between thefirst liquid crystal substrate 250 and the backlight module 210. Thesecond panel 230 is disposed in the light emitting side B; the firstpanel 220 is disposed between the backlight module 210 and the secondpanel 230. The second panel 230 includes a second liquid crystalsubstrate 260 and a second polarizer 270; the second liquid substrate260 is disposed between the second polarizer 270 and the first panel220. The synchronization device 280 is electrically connected to thebacklight module 210, the first liquid crystal substrate 250, and thesecond liquid crystal substrate 260. During a frame time, the backlightmodule 210, the first liquid crystal layer 250, and the second liquidcrystal layer 260 are synchronously driven by the synchronization device280.

Continuing reference to FIG. 2, the backlight module 210 may includematrix backlight units 212; each of the backlight units 212 includes onered LED 212 a, one green LED 212 b, and one blue LED 212 c. Hence, thebacklight module 210 can sequentially emit red, green, and blue light(not drawn). In particular, in the short span of human visual retention,the rapid switching of red, green, and blue light emitted from the redLED 212 a, the green LED 212 b, and the blue LED 212 c, respectively,results in a color mixing effect. This technique is called the ColorSequential Method. Therefore, the 3D display apparatus 200 of thepresent invention can omit the use of color filters. However, thepresent invention does not limit the model of the backlight module 210;any backlight module capable of sequentially emitting a plurality ofcolor light is within the scope of the present invention.

Referring to FIG. 2, the first liquid crystal substrate 250 includes afirst active device array substrate 252, a first opposite substrate 254,and a first liquid crystal layer 256. The first active device arraysubstrate 252 includes matrix first-pixel units 252 a; each of thefirst-pixel unit 252 a corresponds to backlight units 212. The firstopposite substrate 254 is disposed opposite to the first active devicearray substrate 252. The liquid crystal layer 256 is disposed betweenthe active device array substrate 252 and the opposite substrate 254.

Similarly, the second liquid crystal substrate 260 includes a secondactive device array substrate 262, a second opposite substrate 264, anda second liquid crystal layer 266. The second active device arraysubstrate 262 includes matrix second-pixel units 262 a; each of thesecond-pixel units 262 a corresponds to backlight units 212. The secondopposite substrate 264 is disposed opposite to the second active devicearray substrate 262. The second liquid crystal layer 266 is disposedbetween the active device array substrate 262 and the second oppositesubstrate 264.

In addition, the 3D display apparatus 200 of the present invention needsonly one set of polarizers, namely the first polarizer 240 and thesecond polarizer 270 in order to generate quality images. The firstpolarizer 240 is disposed between the backlight module 210 and the firstpanel 220; the second polarizer 270 is disposed at a side of the secondpanel 230 away from the first panel 220. In particular, the polarizingdirection of the first polarizer 240 is substantially perpendicular tothe polarizing direction of the second polarizer 270.

As shown above, one of the features of the 3D display apparatus 200 ofthe present invention includes the omission of color filters, therebyimproving panel transmission rate of the first panel 220 and the secondpanel 230 by around 15%. Color images are generated by directapplication of the plurality of color light (not drawn) provided by thebacklight module 210 of the present invention, in combination with theColor Sequential Method for mixing the emitted color light. By alsoapplying the DFD technique on the first panel 220 and the second panel230, high resolution color 3D images are generated.

In more detail, if for basis of calculation the acceptable imagebrightness value for observer P is 200 nits, and the panel transmissionrate of the first panel 110 and the second panel 120 of the conventional3D display apparatus 100 in FIG. 1A and FIG. 1B is 5%, then the requiredbrightness value from the cold cathode fluorescent light source 130 is:200(nits)/(5%*5%)=80,000(nits)

However, the panel transmission rate of the first panel 220 and thesecond panel 230 of the 3D display apparatus 200 is improved to 15%, soin actuality, the required brightness from the backlight module 210 isonly:200(nits)/(15%*15%)=8,888(nits)

In light of the above-mentioned, the actual brightness required (8,888nits) from the backlight module 210 of the present invention is aboutone tenth of the brightness required (80,000 nits) from the conventionalcold cathode fluorescent light source 130. Therefore, there are drasticsavings with brightness loss and power consumption to be gained from thebacklight module 210.

As shown in FIG. 3, during the frame of time, a first image E1,generated by the first liquid crystal substrate 250, and a second imageE2, generated by the second liquid crystal substrate 260, are combinedto form one 3D image E3. In particular, because the brightness of thefirst image E1 is not equal to the brightness of the second image E2,the 3D image E3 is generated by the DFD technique.

It should be noted that another feature of the 3D display apparatus 200of the present invention is that, during the frame time, thesynchronization device 280 coordinates color light sequentially emittedfrom the backlight module 210 with the image information generated bythe first liquid crystal substrate 250 and the second liquid crystalsubstrate 260. In other words, with the control of the synchronizationdevice 280, this 3D display apparatus 200 can generate quality color 3Dimages and consequently, avoid problems of untrue colors andunsuccessful generations of 3D images.

As shown in FIG. 3, during the frame time, the synchronization device280 receives a first driving signal S1 from the backlight module 210 andgenerates a second driving signal S2 and a third driving signal S3,sends the second driving signal S2 to the first liquid crystal substrate250, and sends the third driving signal S3 to the second liquid crystalsubstrate 260. At this time, the backlight module 210 is the activelydriven device; the first liquid crystal substrate 250 and the secondliquid crystal substrate 260 are passively driven devices.

However, the active/passive driving schemes between the backlight module210, the first liquid crystal substrate 250, and the second liquidcrystal substrate 260 are not limited to what is shown in FIG. 3. Forexample, alternate driving schemes may be found in FIG. 4 to FIG. 6.

Referring to FIG. 4, during the frame time, the synchronization device280 receives a first driving signal H1 from the first liquid crystalsubstrate 250 and generates a second driving signal H2 and a thirddriving signal H3, sends the second driving signal H2 to the backlightmodule 210, and sends the third driving signal H3 to the second liquidcrystal substrate 260. At this time, the first liquid crystal substrate250 is the actively driven device; the backlight module 210 and thesecond liquid crystal substrate 260 are passively driven devices.

Referring to FIG. 5, during the frame time, the synchronization device280 receives a first driving signal L1 from the second liquid crystalsubstrate 260 and generates the second driving signal L2 and the thirddriving signal L3, sends the second driving signal L2 to the backlightmodule 210, and sends the third driving signal L3 to the first liquidcrystal substrate 250. At this time, the second liquid crystal substrate260 is the actively driven device; the backlight module 210 and thefirst liquid crystal substrate 250 are passively driven devices.

During the frame time, FIG. 6 shows that the synchronization device 280can synchronously generate a first driving signal T1, a second drivingsignal T2, and a third driving signal T3 and send the signals to thebacklight module 210, the first liquid crystal substrate 250, and thesecond liquid crystal board 260, respectively. At this time, thesynchronization device 280 is the actively driven device; the backlightmodule 210, the first liquid crystal substrate 250 and the second liquidcrystal substrate 260 are the passively driven devices. Based on theabove, any driving schemes capable of coordinating the driving of thebacklight module 210, the first liquid crystal substrate 250, and thesecond liquid crystal substrate 260 is within the realm of thisinvention.

FIG. 7 is an exploded view of another embodiment of the 3D displayapparatus of the present invention. Referring to FIG. 7, the samecomponents are given the same numbering. Different from theaforementioned 3D display apparatus 200 in FIG. 2 and FIG. 3, this 3Ddisplay apparatus 300 includes an additional third liquid crystalsubstrate 310 disposed between the first liquid crystal substrate 250and the second liquid crystal substrate 260. In other words, more thantwo liquid crystal substrates can be used to generate color 3D images.

As shown in the embodiment of FIG. 7, during the frame time, thesynchronization device 280 coordinates color light sequentially emittedfrom the backlight module 210 with the image information displayed bythe first liquid crystal substrate 250, the second liquid crystalsubstrate 260, and the third liquid crystal substrate 310.

More specifically, during the frame time, the first image F1 generatedby the first liquid crystal substrate 250, the second image F2 generatedby the second liquid crystal substrate 260, and the third image F3generated by the third liquid crystal substrate 310 can be combined togenerate a 3D image F4. In particular, due to the brightness differencebetween the first image F1, the second image F2, and the third image F3,the DFD technique can be applied to generate a 3D image F4. Here, thepresent invention does not set any limitations on the number of liquidcrystal substrates, and therefore the designer has the option to changethe number of substrates based on the desired depth of the 3D images.

To illustrate further, an example of the driving scheme between eachcomponent of this 3D display apparatus 300 is as follows. During theframe time, the synchronization device 280 receives a first drivingsignal J1 from the first liquid crystal substrate 250 and generates asecond driving signal J2, a third driving signal J3, and a fourthdriving signal J4, sends the second driving signal J2 to the backlightmodule 210, sends the third driving signal J3 to the third liquidcrystal substrate 310, and sends the fourth driving signal J4 to thesecond liquid crystal substrate 260. Here, the present invention doesnot set any limitations on the active/passive driving schemes betweenthe backlight module 210 and the liquid crystal substrates 250, 260, and310.

In summary, the 3D display apparatus in the present invention has atleast the following advantages:

This 3D display apparatus avoids the use of color filters, placed by abacklight module that sequentially emits a plurality of color light forthe display of color images, and such arrangement results in theincrease of the panel transmission rate. Consequently, brightnessdegradation is minimized and power consumption of the backlight moduleis decreased. In addition, problems such as untrue colors andunsuccessful generations of 3D images are avoided with the applicationof the synchronization device. During the frame time, thesynchronization device synchronously drives the backlight module alongwith a plurality of liquid crystal substrates, coordinating color lightsequentially emitted from the backlight module with the imageinformation generated by the liquid crystal substrates.

Although the invention has been described with reference to theembodiments thereof, it will be apparent to one of the ordinary skillsin the art that modifications to the described embodiments may be madewithout departing from the spirit of the invention. Accordingly, thescope of the invention will be defined by the attached claims not by theabove detailed description.

1. A three-dimensional display apparatus, comprising: a backlightmodule, wherein said backlight module has a light emitting side, andsaid backlight module sequentially emits a plurality of color light; afirst panel, wherein said first panel is disposed at the light emittingside, said first panel comprising a first polarizer and a first liquidcrystal substrate, and said first polarizer is disposed between saidfirst liquid crystal substrate and said backlight module; a secondpanel, wherein said second panel is disposed at the light emitting side,said first panel is disposed between said backlight module and saidsecond panel, said second panel comprising a second liquid crystalsubstrate and a second polarizer, and wherein said second liquid crystalsubstrate is disposed between said second polarizer and said firstpanel; and a synchronization device electrically connected to saidbacklight module, said first liquid crystal substrate, and said secondliquid crystal substrate, wherein during a frame time, said backlightmodule, said first liquid crystal substrate, and said second liquidcrystal substrate are synchronously driven by said synchronizationdevice; and a third liquid crystal substrate disposed between said firstpanel and said second panel, wherein during said frame time, saidsynchronization device receives a first driving signal from said firstliquid crystal substrate and generates a second driving signal, a thirddriving signal, and a fourth driving signal, sends said second drivingsignal to said first backlight module, sends said third driving signalto said third liquid crystal substrate, and sends said fourth drivingsignal to said second liquid crystal substrate.
 2. The three-dimensionaldisplay apparatus as claimed in claim 1, wherein said synchronizationdevice coordinates, during the frame time, said color light sequentiallyemitted from the backlight module with image information displayed bysaid first liquid crystal substrate and said second liquid crystalsubstrate.
 3. The three-dimensional display apparatus as claimed inclaim 1, wherein during said frame time, said synchronization devicecoordinates said color light sequentially emitted from said backlightmodule with image information displayed by said first liquid crystalsubstrate, said second liquid crystal substrate, and said third liquidcrystal substrate.
 4. The three-dimensional display apparatus as claimedin claim 1, wherein during said frame time, a first image is generatedby said first liquid crystal substrate, a second image is generated bysaid second liquid crystal substrate, and a third image is generated bysaid third liquid crystal substrate, and the three images are combinedto form a three-dimensional image.
 5. The three-dimensional displayapparatus as claimed in claim 4, wherein the brightness value of saidfirst image, the brightness value of said second image, and thebrightness value of said third image are unequal.
 6. Thethree-dimensional display apparatus as claimed in claim 1, wherein saidbacklight module comprises matrix backlight units, and each of thebacklight units further comprises a red light-emitting diode, a greenlight-emitting diode, and a blue light-emitting diode.
 7. The liquidcrystal display apparatus as claimed in claim 6, wherein said firstliquid crystal substrate comprises: a first active device arraysubstrate, comprising a plurality of matrix first-pixel units, whereineach said first-pixel unit corresponds to backlight units; a firstopposite substrate, wherein said first opposite substrate is disposedopposite to said first active device array substrate; and a first liquidcrystal layer, wherein said first liquid crystal layer is disposedbetween said first active device array substrate and said first oppositesubstrate.
 8. The three-dimensional display apparatus as claimed inclaim 6, wherein said second liquid crystal substrate comprises: asecond active device array substrate, comprising a plurality of matrixsecond-pixel units, wherein each said second-pixel unit corresponds tobacklight units; a second opposite substrate, wherein said secondopposite substrate is disposed opposite to said second active devicearray substrate; and a second liquid crystal layer, wherein said secondliquid crystal layer is disposed between said second active device arraysubstrate and said second opposite substrate.
 9. The three-dimensionaldisplay apparatus as claimed in claim 1, wherein the polarizingdirection of said first polarizer is substantially perpendicular to thepolarizing direction of said second polarizer.